mcgrevy



March 19, 1957 G. F. MoGRl-:VY 2,786,087

BREAKER POINT MECHANISM 'Filed May 11, 1954 z sheets-sheet 1 March 1 9, 1957 G. F. MoGREvY I 2,786,087

BREAKER POINT MECHANISM www.

United States Patent() BREAKER POINT MECHANISM George F. McGrevy, Springfield, Mass., assignor, by mesne assignments, to Globe-Union Inc., a corporation of Delaware Application May 11, 1954, Serial No. 428,898

6 Claims. (Cl. 12S-146.5)

breaker point mechanism of simplied and improved construction, adaptable to quantity production manufacture at lo-w unit cost.

More particularly, the invention has for an object the provision of a breaker point mechanism, wherein a breaker arm of the flat spring type, an associated insulator and a condenser casing are held together and to an ear on a metallic supporting member by a single screw, in such a manner that the casing is grounded to the ear and support, the spring breaker arm is electrically connected to `the insulated terminal of the condenser, the spring breaker arm is tensioned and held against turning in its insulator and the latter is held against turning on said ear.

The invention will be disclosed with reference to .the ione illustrative embodiment of it in the accompanying :drawings in which:

Fig. 1 is an enlarged front elevational view of a breakerpoint mechanism embodying the invention;

Fig. 2 is an enlarged top plan view thereof;

Fig. 3 is an enlarged end elevational view. taken from the left of Fig. l;

Fig. 4 is an enlarged sectional elevational view, :taken on the line 4-4 of Fig. 3;

IFig. 5 is a front elevational view of the fiat spring 'breaker arm;

Fig. 6 is a front elevational view of the supporting insulator for the breaker spring arm; and

Fig. 7 is an end view of the insulator support, taken from the right of Fig. 6.

Referring to these drawings; the breaker-point mechanism includes a flat supporting plate 1 (Fig. l), having a hole 2 and a slot 3 extending therethrough, and respectively adapted to receive fastening screws 4 and 5, whereby the plate 1 may be clamped, as shown in Fig. 3, tightly against a suitable support, such for example, as the stator plate of a magneto, indicated in part by dotted lines at 6. The slot 3 (Fig. 1) is curved from the center of hole 2 to allow the plate 1 to be swung about the screw 4 as a pivot and bodily shift the breaker-point mechanism toward or away from a cam, such as that indicated by dotted lines at 7, which aotuates the mechamsm.

The plate 1 has a part 8, bent outwardly therefrom at right angles, and the lower end of this part is bent at right .angles forming an ear 9, to the upper face of which is fixed the stationary breaker point 10. Near its other end, the plate 1 has another ear 11 which is bent forwardly therefrom at right angles and has extending therethrough a non-circular opening 12 (rectangular as herein shown). rIThis ear 11 supports the breaker arm and the condenser in a special manner, as will later be described in detail. The plate 1 has near its rst-named 2,786,087 Patented Mar. 19, 1957 end a third ear 13 bent forwardly therefrom at right angles and slotted to receive and support the usual felt wiper 14, which is adapted to ride on the periphery of cam 7.

The breaker arm is shown separately in Fig. 5. It consists of a flat metallic spring 15, bent intermediate its ends as shown and carrying on one end a breaker point 16. Adjacent the latter is a cam follower 17 made of suitable insulating material. As shown, the follower has oppositely out-turned flanges at one end, which are fixed to the spring 15 by rivets 18 and 19, the head of rivet 19 being in this case the `breaker point 16. The other end `of spring 15 has a single hole therethrough to receive a retaining screw.

The breaker arm is secured to the ear 11 through the intermediary of an insulator 20, shown separately in Figs. 6 and 7, and a metallic condenser casing 21 usually of cylindrical form. The casing 21 has as a closure for one end thereof a disk 23 which is made of suitable insulating mateiial and from which projects outwardly a metallic post 22. The latter forms one terminal of the usual condenser which is contained within the casing 21, the other terminal consisting of the casing itself, a portion of which is crimped over against the outer face of disk 23. The post 22 is tapped to receive the one retaining screw 24. The insulator 20* (Figs. 6 and 7) has a hole 25 therethrough to receive lthe post 22 and on its rear face (Fig. 7) a non-circular projection 26 (rectangular as herein shown), adapted to fit in the described opening 12 .in the ear 11. The upper and lower edges of projection 26 abut the upper and lower walls of the opening 12 and these interengaging parts prevent the insulator from turning. The insulator 20 has in its outer end face and its rounded lower end a groove 27 with side walls 28 and the spring 15 when in place in this groove has its edges in abutment with the side Walls 2S to prevent relative turning movement.

-In assembling the parts, the insulator 20 is engaged with one face of ear 11 with the projection 26 iitting into opening 12, as described. The post 22 on cou- ;denser casing 21 is then inserted through hole 25 in insulator 20 until the annular, crimped over portion of the adjacent end wall of casing 21 ahuts the opposite face of ear 11. The spring 15 is put in place with the breaker point 16 on its free end lying on top of the fixed breaker point 10 and the bend therein lying in the groove 27 near the lower rounded corner 29 of the insulator. Then, the screw 24 is inserted through the hole in the upper end of the spring 15 and the latter is pressed toward the insulator 20 until the screw can be engaged in the tapped opening in post 22. The screw is' then tightened until the spring 15 is drawn into the groove 27 and pressed tightly against the insulator Ztl and the latter and casing 21 are tightly clamped against opposite faces of ear 11.

It will thus be seen that the invention pro-vides an improved mounting of the parts of a breaker point mechanism, whereby a single screw selves to hold all the parts in proper relationship to an ear on a metallic supporting plate, to electrically connect the condenser casing to the plate and its insulated terminal to the spring breaker arm, and to tension the spring breaker arm, the latter and its insulator being held against turning by interengaging parts and the insulator and ear having interengaging parts to hold the insulator from turning. The parts of the mechanism are few in number and inexpensive to manufacture; they are adapted for quick and easy assembly; and the novel interengagement of the parts maintains them accurately in proper relationship.

What is claimed is:

l. Breaker point mechanism, comprising, a supporting plate having at spaced locations thereon iii-st and second out turned ears, a breaker point fixed to one face of the first ear, the second ear having an opening therethrough, a metallic casing housing a condenser and forming one electrical terminal thereof, said casing having one end wall composed of an outer conducting portion abutting one face of the second ear and an inner non-conducting portion, a post of conducting material projecting out- .wardly from said last-named .portion through said opening and forming the other terminal of the condenser, `an :insulator abutting .the opposite face of the second ear and hav-ing an opening through which said post extends', a breaker arm consisting of a fiat electrically-conductive spring and a breaker point and cam follower xed thereto, and a screw extending .through the breaker arm near one end and threaded into said metallic post for clamping the spring to the insulator and post and for clamping the insulator and the casing to opposite faces of the second ear, and for grounding the condenser casing to the support and electrically connecting the breaker'arm to the second-named terminal of the condenser.

2. The combination, as claimed in claim l, in which said face of the rst ear is -disposed at au angle to said faces of the second ear and the breaker-pointcarrying end of the spring breaker arm is bent at an angle to the fixed end thereof, said spring breaker arm being placed under tension by the clamping of it to said insulator by said screw.l

3. The combination, as claimed in claim 2, in which the insulator has a rounded end around which the bent spring breaker arm passes.

4. The combination, as claimed in claim 2, in which the insulator has a groove lin which the spring breaker arm is engaged to prevent it from turning.

5. The combination, as claimedin claim 2, in which the Cil portion, the latter forming one terminal 'of the condenser,

post of conducting material fixed to and projecting outwardly from the non-conducting portion of said end wall and forming the other terminal of the condenser, said post having a tapped hole therein; a supporting member having a first part to which the other breaker point is fixed and a secondpart having opposed flat faces and an opening therethrough extending between said faces, an insulating block having opposed faces and an opening `through it connecting said faces, one of said faces of said block engaging one of said faces of the second part, the conducting portion of said end wall engaging the other of said faces of the second part and said post extending through both said openings, and a single screw passing through the other end of said Hat spring arm and threading into the tapped hole in said post for clamping the spring against the -insulator and post and for clamping the insulator and `the conducting portion of said end wall against said opposite faces of the second part.

References Cited in the le of this patent UNITED STATES PATENTS 2,464,779 yiBrov/nlee et al Mar. 1.5, 1949 2,570,797 Guillel'mn Oct. V9, 1 951 2,684,394 Guillermin July 20, 1954 

